When viewing an ap projection of the upper cervical spine open mouth technique you notice that the base of the skull is superimposed over the dens. what position error caused this?

It is possible that the error is due to patient’s neck was extended too far.

There are certain rules for the patient positioning during the open-mouth technique. For example, patient’s shoulders should be at equal distances from the image receptor to avoid rotation and the head should be positioned so the skull and the lower margin of the upper incisors are perpendicular (90 degrees) to the image receptor.

the dark variety, as they are not visible on the dark tree barks

explanation: